The invention relates to a planar sputtering target having a surface area of more than 0.5 m2 or a tubular sputtering target having a length of at least 1.0 m, each consisting of a silver base alloy and at least one further alloy component selected from indium, tin, antimony, and bismuth accounting jointly for a weight fraction of 0.01 to 5.0% by weight.
The invention also relates to a method for producing a planar sputtering target having a surface area of more than 0.3 m2 or a tubular sputtering target having a length of at least 1.0 m from a silver base alloy, comprising melting an alloy having a nominal composition of silver and at least one further alloy component selected from indium, tin, antimony, and bismuth accounting jointly for a weight fraction of 0.01 to 5.0% by weight, casting the molten material into a mould and thus forming a form body from the silver base alloy, and reforming the form body into a sputtering target.
Sputtering targets of this type are used as cathode material for producing layers by means of high vacuum-based sputtering in tubular or planar design, such as, for example square targets or strip-shaped targets. Cathode sputtering is used, for example, to provide optical storage media or substrates with reflective or partially reflective layers during the production of liquid crystal displays or OLED displays.
A sputtering target for producing layers with high reflectivity in the visible spectral range is known from EP 1 489 193 A1. The target material consists of a silver alloy with additives accounting for 0.01-5.0% by weight, whereby at least one of the elements, indium, tin, antimony and/or bismuth, is present therein. Said material is characterised by its high resistance to corrosion and ambient conditions in sulphur-containing atmospheres.
The production usually involves melting an alloy and casting it into a mould, often followed by a reforming step such as forging, rolling or pressing.